<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .fu{background-color: #facaca;}
        .fu>div{width: 100px;
        height: 100px;
        }
        .z1{background-color: #f48b8b;
        position: relative;
        z-index: 10;/*层级关系 数字越大越靠上,一般默认为0*/}
        .z2{background-color: #ed6060;
        position: relative;
        right: 50px;
        bottom: 50px;
        }
        .z3{background-color: #ef3131;}
    </style>
</head>
<body>
<div class="fu">
    <div class="z1"></div>
    <div class="z2"></div>
    <div class="z3"></div>
</div>
</body>
</html>